HOM LOSSES AT THE INTERACTION REGION rc OF THE B FACTORY

Masking at the Interaction Region (IR) will presumably reduce the synchrotron radiation background in the detector. One possible layout of the IR for the B factory, depicted in Fig. 1, shows a rather complicated system of masks. A bunch passing each mask will generate RF waves. These waves (usually called higher order modes, HOMs) will be absorbed in the beam pipe wall producing additional heating and, interacting with the beam, kicking particles in the radial and azimuthal directions. This may change the bunch motion and its emittance. These effects are estimated in the present note.